German Patent Specification No. 2,236,389 discloses a process and equipment for purifying gases. The equipment includes a roll-shaped hollow body with disks which extend transversely to its longitudinal axis over its outer circumference and which are arranged at a mutual distance and dip into a wetting fluid in the lower part of the housing surrounding the roll body and the disks. There are diametrically opposite channels parallel to the longitudinal axis of the roll body which permit introducing and discharging the gas which is to be purified. The gas to be purified flows around the internally heated roll body in the circumferential direction between the disks. During the rotary movement of the half-immersed roll body, solids layers are continuously formed on the disks emerging from the fluid and on the exposed circumferential section of the roll body, which layers react with the substances contained in the gases passed over them. Inevitably, layers of different degrees of drying then come into contact with the gases to be purified so that, even before drying, wet reactions lead to the loss of the layer and hence to interference with the course of the reaction. In many cases, reactive dry layers are then no longer formed, leading to complete failure of the process. The purification of gases which are laden with pollutants and the temperature of which is substantially below the drying temperature of the reaction layer, is not feasible with this known process, because the quantity of heat required for drying the layers must be supplied via the roll body and the disks, which are continuously cooled by the gas flowing past them. A further disadvantage of this known process is that the gas flow paths in the reaction chambers formed between the disks are not variable, so that it is not possible to influence the mono-reactive behavior of a large number of pollutant compounds.